Although opioid medications are recognized as a highly effective treatment for moderate and severe acute pain and chronic cancer pain, the use of these medications for chronic non-malignant pain is controversial because of concerns about long-term efficacy, safety, and the risk of abuse, addiction and diversion. Theoretically, buprenorphine, a partial mu-agonist, may be an attractive option for long term opioid analgesic therapy because, compared to full mu-agonists, it has a high safety profile, a low level of physical dependence, and mild withdrawal symptoms on cessation. Its potential utility for the treatment of chronic pain in selected patients gains support from trials of a transdermal formulation and a survey in which the sublingual (SL) formulation was used to treat chronic pain patients. These clinical observations did not evaluate the potential utility of buprenorphine in patients with pain and a history of substance abuse or aberrant drug-related behavior (e.g. unsanctioned dose escalation). They did not illuminate outcomes related to abuse behaviors and did not clarify the fundamental issues in medication administration that must be appreciated before the drug can be more widely used in the population of opioid-treated pain patients. At this date, it is possible to capitalize on existing knowledge of the pharmacology of buprenorphine, combined with its use as a treatment for dependence, acute pain and the limited experience with chronic pain and propose a conservative treatment protocol for chronic pain patients. A protocol based on expert opinion can provide a starting point for the proposed prospective cohort study that, in turn, will clarify the specific treatment elements that can be incorporated into future trials with the challenging population with both pain and substance abuse histories or aberrant drug-related behavior. To this end, the specific aims of this R21 application are: 1) To create a protocol for the use of SL buprenorphine in the treatment of chronic pain in populations with substance use disorders. This protocol will be developed by an expert panel comprising leaders in pain medicine, addiction medicine and buprenorphine pharmacology. 2) To evaluate this protocol in regards to its feasibility and a range of outcomes related to safety and effectiveness. Subjects would include 40 patients with chronic pain and substance abuse histories or current aberrant drug-related behavior. Subjects will be followed up for 6 months. The prevalence of chronic pain in the general population is conservatively estimated at 10 to 20%; advancement in knowledge of treatment protocols for an opioid medication that could be safely and effectively used with selected populations of chronic pain patients would provide a significant public health benefit. [unreadable] [unreadable] [unreadable]